The present invention relates to ice fishing in general, and specifically to heat type devices for preventing freezing of water in a hole opening through ice.
Prior art heating devices for maintaining open ice fishing holes have not been without significant drawbacks. One type of heating device shown in U.S. Pat. No. 4,612,910 to Williams utilizes a bouyant water proof canister which is floated in the hole, filled with combustible material, and ignited. As the material burns, heat is produced and conducted through the canister. While the water within the ice hole is warmed nicely with this method, the canister is free to bob around in the hole and can easily contact the fishing line which passes through the same hole. Such contact is detrimental and may result in cut or damaged line.
U.S. Pat. No. 4,006,732 to Schumm discloses a gas heater which maintains an open hole and which is anchored to the hole with special legs designed for the purpose. However, the complexity of the Schumm patent is apparent, and the cost of producing such a device can be prohibitive. Schumm also lists several other pertinent patents and the associated drawbacks of each.
Many of the aforementioned disadvantages are overcome by using a device known as a water spitter and disclosed in Panfish, by Sternberg et al, 1983, p. 138. The water spitter disclosed in the prior art is disadvantageous in that little control over the throughput of the device (through thermosiphonic action) is available. Additionally, the prior art water spitter is non-transportable, and requires a significant warm-up period to generate a puddle of water sufficient for operation.